1. Field of the Invention
The present invention relates to differential assemblies, and more particularly to a ultra narrow differential assembly for motor vehicles having a device for adjusting position of a ring gear relative to an axle housing and bearing preload.
2. Description of the Prior Art
Conventionally, differentials well known in the prior art, are arranged in a power transmission system of a motor vehicle to allow a pair of output shafts operatively coupled to an input shaft to rotate at different speeds, thereby allowing the wheel associated with each output shaft to maintain traction with the road while the vehicle is turning. Conventional differentials include a differential case defining a gear chamber, and disposed therein, a differential gear set including at least one input pinion gear, and a pair of output side gears non-rotatably coupled to corresponding axle shafts. Such a device essentially distributes the torque provided by the input shaft between the output shafts. This type of differentials is known in the art as an open differential, i.e. a differential where movements of its various internal components are not restricted in any significant fashion.
Normally, the differential assemblies comprise a differential case and a differential pinion shaft is disposed within the differential case for rotatably supporting a set of pinion mate gears. In turn, the pinion mate gears drivingly engage a pair of opposite side gears for allowing differential rotation therebetween. Typically, the side gears are splined to corresponding axle shafts.
The conventional differential assemblies are multipart and relatively voluminous aggregates, expensive in manufacturing and labor extensive in assembling.
Thus, there is a need for a differential assembly that is simple, compact and inexpensive to manufacture.
The present invention provides a novel arrangement of an ultra narrow differential assembly comprising a differential housing, a ring gear rotatably supported within the differential housing about a central axis, a set of differential pinion mate gears rotatably mounted to the ring gear, a pair of opposite side gears drivingly engaging the differential pinion mate gears for establishing driving connection between the ring gear and the side gears and allowing differential rotation between the side gears, and an adjustment device for selectively adjusting position of the ring gear relative to the differential housing.
Preferably, the adjustment device includes a pair of adjustment members selectively positionable within the differential housing coaxially to the central axis on opposite sides of the ring gear. The adjustment members have a substantially cylindrical threaded outer peripheral surfaces engaging with corresponding internally threaded bores provided in the differential housing for selectively axially positioning the adjustment members therewithin.
The differential pinion mate gears are rotatably mounted in complementary recesses in a central bore of the ring gear in a free-floating manner.
The differential assembly of the present invention further comprises a pair of ball bearing assemblies each disposed between one of face surfaces of the ring gear and one of the adjustment members for rotatably supporting the ring gear within the differential housing. Preferably, each of the bearing assemblies includes an inner race integrally formed on one of the face surfaces of the ring gear, an outer race integrally formed on an inner face surface of the adjusting ring, and a plurality of spherical rolling elements.
In accordance with the first exemplary embodiment of the present invention, each of the adjustment members has a radially inwardly protruding retaining flange provided for limiting axial outward movement of the corresponding side gear, and a pair of thrust bearings is provided each disposed between one of the side gears and the retaining flange of the corresponding adjusting members.
Alternatively, in accordance with the second exemplary embodiment of the present invention, the differential assembly comprises a pair of opposite radially inwardly protruding retaining rings fitted within complementary annular recesses formed on the substantially cylindrical central bore of the ring gear for limiting axial outward movement of the side gears.
Therefore, the novel differential assembly in accordance with the present invention provides a simple, ultra narrow, inexpensive in manufacturing and easy to assemble differential assembly.